In optical fiber communications, optical fibers are often constructed from a number of sections each having an optical pathway formed therein. The sections are aligned end to end such that light passing through a first optical pathway section can continue traveling through the optical pathway of a second optical fiber section.
In theory, the ends are placed adjacent to each other and the light passes from one end to the next. However, in the field, the environment of the optical network can provide forces that move one optical fiber section with respect to another and, thereby, the transmission of light signals between the optical fiber sections can be attenuated or disrupted. Alternatively, or in combination with the just-described movement, “dirt” from the environment can contaminate one end and/or the other end of two adjacent optical fiber sections so as to attenuate or disrupt transmission of light signals. As such, typically, at least the ends of two adjacent optical fiber sections are connected to each other in a manner (e.g., with an optical connector) intended to maintain the alignment and/or prevent the contamination of the optical pathway with respect to the two optical fiber sections.
In some instances, an optical fiber is analyzed to determine if a disconnect in the optical pathway exists and/or where the disconnect is located. For example, in some instances, it may be that the location of a fault within an optical fiber is to be located so the fault can be rectified.
Oftentimes, this is accomplished by disconnecting the optical fiber from a transmitter, connector, and/or receiver so that the optical pathway of the optical fiber can be tested. The testing typically involves attaching an end of an optical fiber to a separate testing apparatus.
Optical Time-Domain Reflectometry (OTDR) is one method used to locate such faults (e.g., disconnect in the fiber) in fiber optic networks. In this method, a laser pulse is sent down a fiber to be tested and reflected back by a fault in the optical pathway. The reflected laser pulse is then received by a photodetector. The time period elapsed since the signal was sent indicates how far down the pathway the fault is located.
However, the use of a separate testing apparatus to locate faults within an optical fiber can be time consuming and costly. In order to test the optical pathway, the testing equipment can be connected via a fiber access point which adds components to the optical network and can degrade the signal as it travels along the optical pathway. Alternatively, in systems where optical pathways forming an optical network are constructed using a number of optical fibers, each forming a section of the pathway, an end of an optical fiber section can be located and disconnected from the optical network.
In such systems, each optical fiber section is attached to the end of another optical fiber section. In some embodiments, an end of one of the optical sections can be accessed and the testing apparatus can be connected thereto.
Such methods can result in periods where the fiber is out of the communications network and, therefore, can result in network downtime. However, the use of a separate testing apparatus to locate faults within an optical fiber can be time consuming and costly.